Putrescine improves salt tolerance of wheat seedlings by regulating ascorbate and glutathione metabolism, photosynthetic performance, and ion homeostasis

Abstract

In the world, salt stress limits wheat growth and production. Salt stress often induces oxidative damage by leading to the accumulation of excess reactive oxygen species (Kapoor and Hasanuzzaman 2020). Fortunately, plants can counteract oxidative damage through the antioxidant system (Soliman et al. 2020). In the antioxidant system, reduced ascorbate (AsA) and reduced glutathione (GSH) are major antioxidants (Mohsin et al. 2020). Their contents can be regulated through their regeneration and biosynthesis (Zhu et al. 2021). l-galactono-1,4-lactone dehydrogenase (GalLDH) and gamma-glutamylcysteine synthetase (γ-ECS) are the key enzymes for the biosynthesis of AsA and GSH, respectively. Ascorbate-glutathione (AsA-GSH) cycle is in charge of their regeneration. In this cycle, ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) are in charge of their operation (Maslennikova et al. 2022). Through this cycle, plants can not only realise AsA and GSH regeneration but also scavenge hydrogen peroxide (H 2 O 2 ). Therefore, the metabolism of ASC and glutathione in plants played vital roles in counteracting salt stress.